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Re: [Caml-list] Re: Cryptokit and HMAC-SHA256
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Date: 2010-07-22 (08:49)
From: Sylvain Le Gall <sylvain@l...>
Subject: Re: Cryptokit and HMAC-SHA256

On 22-07-2010, Goswin von Brederlow <> wrote:
> Dario Teixeira <> writes:
>> Hi,
>>> If you decide to code the solution and provide the patch, I will be
>>> happy to apply it to cryptokit (if the main author of cryptokit accepts
>>> it, of course).
>> I'm attaching the patches adding support for HMAC-SHA256 and HMAC-RIPEMD160
>> (I don't need the latter, but for the sake of completeness it seemed silly
>> not to support it as well).  Note that these are *very* straightforward
>> patches -- kudos to Xavier for making Cryptokit so easy to extend.
>> The caveat is that I'm not a cryptographer.  I did, however, verify that
>> these new HMACs pass all the test cases listed in RFC4231 (for HMAC-SHA256)
>> and RFC2286 (for HMAC-RIPEMD160).
>> Thanks for your attention!
>> Cheers,
>> Dario Teixeira
> While you are patching cryptokit anyway would it be possible to also add
> functions to work on Bigarrays?

Well in fact, HMAC-SHA256 and  HMAC-RIPEMD160 has been implemented in
the source code, but never released. So no patching involved.

> One huge advantage of bigarray is that the data region is allocated
> outside the GC heap and will never move. That means one can use
> enter_blocking_section() / leave_blocking_section() while calculating
> the checksum for a block of data. For multithreaded applications that
> can speed up the program by the number of cores present.

Submit a feature request with as much data as possible on the BTS:

Sylvain Le Gall